diff --git a/tests/test-copies.t b/tests/test-copies.t
new file mode 100644
--- /dev/null
+++ b/tests/test-copies.t
@@ -0,0 +1,435 @@
+
+  $ cat >> $HGRCPATH << EOF
+  > [alias]
+  > l = log -G -T '{rev} {desc}\n{files}\n'
+  > EOF
+
+  $ REPONUM=0
+  $ newrepo() {
+  >     cd $TESTTMP
+  >     REPONUM=`expr $REPONUM + 1`
+  >     hg init repo-$REPONUM
+  >     cd repo-$REPONUM
+  > }
+
+Simple rename case
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg mv x y
+  $ hg ci -m 'rename x to y'
+  $ hg l
+  @  1 rename x to y
+  |  x y
+  o  0 add x
+     x
+  $ hg debugpathcopies 0 1
+  x -> y
+  $ hg debugpathcopies 1 0
+  y -> x
+Test filtering copies by path. We do filtering by destination.
+  $ hg debugpathcopies 0 1 x
+  $ hg debugpathcopies 1 0 x
+  y -> x
+  $ hg debugpathcopies 0 1 y
+  x -> y
+BROKEN: the following command should not include the copy
+  $ hg debugpathcopies 1 0 y
+  y -> x
+
+Copy a file onto another file
+  $ newrepo
+  $ echo x > x
+  $ echo y > y
+  $ hg ci -Aqm 'add x and y'
+  $ hg cp -f x y
+  $ hg ci -m 'copy x onto y'
+  $ hg l
+  @  1 copy x onto y
+  |  y
+  o  0 add x and y
+     x y
+Incorrectly doesn't show the rename
+  $ hg debugpathcopies 0 1
+
+Copy a file onto another file with same content. If metadata is stored in changeset, this does not
+produce a new filelog entry. The changeset's "files" entry should still list the file.
+  $ newrepo
+  $ echo x > x
+  $ echo x > x2
+  $ hg ci -Aqm 'add x and x2 with same content'
+  $ hg cp -f x x2
+  $ hg ci -m 'copy x onto x2'
+  $ hg l
+  @  1 copy x onto x2
+  |  x2
+  o  0 add x and x2 with same content
+     x x2
+Incorrectly doesn't show the rename
+  $ hg debugpathcopies 0 1
+
+Copy a file, then delete destination, then copy again. This does not create a new filelog entry.
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg cp x y
+  $ hg ci -m 'copy x to y'
+  $ hg rm y
+  $ hg ci -m 'remove y'
+  $ hg cp -f x y
+  $ hg ci -m 'copy x onto y (again)'
+  $ hg l
+  @  3 copy x onto y (again)
+  |  y
+  o  2 remove y
+  |  y
+  o  1 copy x to y
+  |  y
+  o  0 add x
+     x
+  $ hg debugpathcopies 0 3
+  x -> y
+
+Rename file in a loop: x->y->z->x
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg mv x y
+  $ hg ci -m 'rename x to y'
+  $ hg mv y z
+  $ hg ci -m 'rename y to z'
+  $ hg mv z x
+  $ hg ci -m 'rename z to x'
+  $ hg l
+  @  3 rename z to x
+  |  x z
+  o  2 rename y to z
+  |  y z
+  o  1 rename x to y
+  |  x y
+  o  0 add x
+     x
+  $ hg debugpathcopies 0 3
+
+Copy x to y, then remove y, then add back y. With copy metadata in the changeset, this could easily
+end up reporting y as copied from x (if we don't unmark it as a copy when it's removed).
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg mv x y
+  $ hg ci -m 'rename x to y'
+  $ hg rm y
+  $ hg ci -qm 'remove y'
+  $ echo x > y
+  $ hg ci -Aqm 'add back y'
+  $ hg l
+  @  3 add back y
+  |  y
+  o  2 remove y
+  |  y
+  o  1 rename x to y
+  |  x y
+  o  0 add x
+     x
+  $ hg debugpathcopies 0 3
+
+Copy x to z, then remove z, then copy x2 (same content as x) to z. With copy metadata in the
+changeset, the two copies here will have the same filelog entry, so ctx['z'].introrev() might point
+to the first commit that added the file. We should still report the copy as being from x2.
+  $ newrepo
+  $ echo x > x
+  $ echo x > x2
+  $ hg ci -Aqm 'add x and x2 with same content'
+  $ hg cp x z
+  $ hg ci -qm 'copy x to z'
+  $ hg rm z
+  $ hg ci -m 'remove z'
+  $ hg cp x2 z
+  $ hg ci -m 'copy x2 to z'
+  $ hg l
+  @  3 copy x2 to z
+  |  z
+  o  2 remove z
+  |  z
+  o  1 copy x to z
+  |  z
+  o  0 add x and x2 with same content
+     x x2
+  $ hg debugpathcopies 0 3
+  x2 -> z
+
+Create x and y, then rename them both to the same name, but on different sides of a fork
+  $ newrepo
+  $ echo x > x
+  $ echo y > y
+  $ hg ci -Aqm 'add x and y'
+  $ hg mv x z
+  $ hg ci -qm 'rename x to z'
+  $ hg co -q 0
+  $ hg mv y z
+  $ hg ci -qm 'rename y to z'
+  $ hg l
+  @  2 rename y to z
+  |  y z
+  | o  1 rename x to z
+  |/   x z
+  o  0 add x and y
+     x y
+  $ hg debugpathcopies 1 2
+  z -> x
+  y -> z
+
+Fork renames x to y on one side and removes x on the other
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg mv x y
+  $ hg ci -m 'rename x to y'
+  $ hg co -q 0
+  $ hg rm x
+  $ hg ci -m 'remove x'
+  created new head
+  $ hg l
+  @  2 remove x
+  |  x
+  | o  1 rename x to y
+  |/   x y
+  o  0 add x
+     x
+BROKEN: x doesn't exist here
+  $ hg debugpathcopies 1 2
+  y -> x
+
+Copies via null revision (there shouldn't be any)
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg cp x y
+  $ hg ci -m 'copy x to y'
+  $ hg co -q null
+  $ echo x > x
+  $ hg ci -Aqm 'add x (again)'
+  $ hg l
+  @  2 add x (again)
+     x
+  o  1 copy x to y
+  |  y
+  o  0 add x
+     x
+  $ hg debugpathcopies 1 2
+  $ hg debugpathcopies 2 1
+
+Merge rename from other branch
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg mv x y
+  $ hg ci -m 'rename x to y'
+  $ hg co -q 0
+  $ echo z > z
+  $ hg ci -Aqm 'add z'
+  $ hg merge -q 1
+  $ hg ci -m 'merge rename from p2'
+  $ hg l
+  @    3 merge rename from p2
+  |\   x
+  | o  2 add z
+  | |  z
+  o |  1 rename x to y
+  |/   x y
+  o  0 add x
+     x
+Perhaps we should indicate the rename here, but `hg status` is documented to be weird during
+merges, so...
+  $ hg debugpathcopies 0 3
+  x -> y
+  $ hg debugpathcopies 1 2
+  y -> x
+  $ hg debugpathcopies 1 3
+  $ hg debugpathcopies 2 3
+  x -> y
+
+Copy file from either side in a merge
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg co -q null
+  $ echo y > y
+  $ hg ci -Aqm 'add y'
+  $ hg merge -q 0
+  $ hg cp y z
+  $ hg ci -m 'copy file from p1 in merge'
+  $ hg co -q 1
+  $ hg merge -q 0
+  $ hg cp x z
+  $ hg ci -qm 'copy file from p2 in merge'
+  $ hg l
+  @    3 copy file from p2 in merge
+  |\   z
+  +---o  2 copy file from p1 in merge
+  | |/   z
+  | o  1 add y
+  |    y
+  o  0 add x
+     x
+  $ hg debugpathcopies 1 2
+  y -> z
+  $ hg debugpathcopies 0 2
+  $ hg debugpathcopies 1 3
+  $ hg debugpathcopies 0 3
+  x -> z
+
+Copy file that exists on both sides of the merge, same content on both sides
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x on branch 1'
+  $ hg co -q null
+  $ echo x > x
+  $ hg ci -Aqm 'add x on branch 2'
+  $ hg merge -q 0
+  $ hg cp x z
+  $ hg ci -qm 'merge'
+  $ hg l
+  @    2 merge
+  |\   z
+  | o  1 add x on branch 2
+  |    x
+  o  0 add x on branch 1
+     x
+It's a little weird that it shows up on both sides
+  $ hg debugpathcopies 1 2
+  x -> z
+  $ hg debugpathcopies 0 2
+  x -> z
+
+Copy file that exists on both sides of the merge, different content
+  $ newrepo
+  $ echo branch1 > x
+  $ hg ci -Aqm 'add x on branch 1'
+  $ hg co -q null
+  $ echo branch2 > x
+  $ hg ci -Aqm 'add x on branch 2'
+  $ hg merge -q 0
+  warning: conflicts while merging x! (edit, then use 'hg resolve --mark')
+  [1]
+  $ echo resolved > x
+  $ hg resolve -m x
+  (no more unresolved files)
+  $ hg cp x z
+  $ hg ci -qm 'merge'
+  $ hg l
+  @    2 merge
+  |\   x z
+  | o  1 add x on branch 2
+  |    x
+  o  0 add x on branch 1
+     x
+  $ hg debugpathcopies 1 2
+  $ hg debugpathcopies 0 2
+  x -> z
+
+Copy x->y on one side of merge and copy x->z on the other side. Pathcopies from one parent
+of the merge to the merge should include the copy from the other side.
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg cp x y
+  $ hg ci -qm 'copy x to y'
+  $ hg co -q 0
+  $ hg cp x z
+  $ hg ci -qm 'copy x to z'
+  $ hg merge -q 1
+  $ hg ci -m 'merge copy x->y and copy x->z'
+  $ hg l
+  @    3 merge copy x->y and copy x->z
+  |\
+  | o  2 copy x to z
+  | |  z
+  o |  1 copy x to y
+  |/   y
+  o  0 add x
+     x
+  $ hg debugpathcopies 2 3
+  x -> y
+  $ hg debugpathcopies 1 3
+  x -> z
+
+Copy x to y on one side of merge, create y and rename to z on the other side. Pathcopies from the
+first side should not include the y->z rename since y didn't exist in the merge base.
+  $ newrepo
+  $ echo x > x
+  $ hg ci -Aqm 'add x'
+  $ hg cp x y
+  $ hg ci -qm 'copy x to y'
+  $ hg co -q 0
+  $ echo y > y
+  $ hg ci -Aqm 'add y'
+  $ hg mv y z
+  $ hg ci -m 'rename y to z'
+  $ hg merge -q 1
+  $ hg ci -m 'merge'
+  $ hg l
+  @    4 merge
+  |\
+  | o  3 rename y to z
+  | |  y z
+  | o  2 add y
+  | |  y
+  o |  1 copy x to y
+  |/   y
+  o  0 add x
+     x
+  $ hg debugpathcopies 2 3
+  y -> z
+  $ hg debugpathcopies 1 3
+
+Create x and y, then rename x to z on one side of merge, and rename y to z and modify z on the
+other side.
+  $ newrepo
+  $ echo x > x
+  $ echo y > y
+  $ hg ci -Aqm 'add x and y'
+  $ hg mv x z
+  $ hg ci -qm 'rename x to z'
+  $ hg co -q 0
+  $ hg mv y z
+  $ hg ci -qm 'rename y to z'
+  $ echo z >> z
+  $ hg ci -m 'modify z'
+  $ hg merge -q 1
+  warning: conflicts while merging z! (edit, then use 'hg resolve --mark')
+  [1]
+  $ echo z > z
+  $ hg resolve -qm z
+  $ hg ci -m 'merge 1 into 3'
+Try merging the other direction too
+  $ hg co -q 1
+  $ hg merge -q 3
+  warning: conflicts while merging z! (edit, then use 'hg resolve --mark')
+  [1]
+  $ echo z > z
+  $ hg resolve -qm z
+  $ hg ci -m 'merge 3 into 1'
+  created new head
+  $ hg l
+  @    5 merge 3 into 1
+  |\   y z
+  +---o  4 merge 1 into 3
+  | |/   x z
+  | o  3 modify z
+  | |  z
+  | o  2 rename y to z
+  | |  y z
+  o |  1 rename x to z
+  |/   x z
+  o  0 add x and y
+     x y
+  $ hg debugpathcopies 1 4
+  $ hg debugpathcopies 2 4
+  $ hg debugpathcopies 0 4
+  x -> z
+  $ hg debugpathcopies 1 5
+  $ hg debugpathcopies 2 5
+  $ hg debugpathcopies 0 5
+  x -> z
+